From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tomas Novotny , Matt Porter , Sekhar Nori Subject: [ 41/75] ARM: davinci: edma: fix dmaengine induced null pointer dereference on da830 Date: Mon, 18 Mar 2013 14:07:04 -0700 Message-Id: <20130318210513.183706082@linuxfoundation.org> In-Reply-To: <20130318210510.203500214@linuxfoundation.org> References: <20130318210510.203500214@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matt Porter commit 069552777a121eb39da29de4bc0383483dbe1f7e upstream. This adds additional error checking to the private edma api implementation to catch the case where the edma_alloc_slot() has an invalid controller parameter. The edma dmaengine wrapper driver relies on this condition being handled in order to avoid setting up a second edma dmaengine instance on DA830. Verfied using a DA850 with the second EDMA controller platform instance removed to simulate a DA830 which only has a single EDMA controller. Reported-by: Tomas Novotny Signed-off-by: Matt Porter Tested-by: Tomas Novotny Signed-off-by: Sekhar Nori Signed-off-by: Greg Kroah-Hartman --- arch/arm/mach-davinci/dma.c | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/arm/mach-davinci/dma.c +++ b/arch/arm/mach-davinci/dma.c @@ -743,6 +743,9 @@ EXPORT_SYMBOL(edma_free_channel); */ int edma_alloc_slot(unsigned ctlr, int slot) { + if (!edma_cc[ctlr]) + return -EINVAL; + if (slot >= 0) slot = EDMA_CHAN_SLOT(slot);